Magnetic and transport properties of YMn6Sn6-xTix (0≤x≤1.0) compounds with HfFe6Ge6-type structure were investigated in the temperature range of 5–400 K. The compounds with low Ti content (x≤0.2) display antiferromagnetic behavior (317 K≤TN≤327 K). The Ti-rich compounds (0.8≤x≤1.0) behave as ferromagnetic in their whole magnetic ordered range (293 K≤TN≤334 K). The intermediate compounds (0.4≤x≤0.6) undergo an antiferro- to ferromagnetic transition with increasing temperature. The metamagnetic transition from antiferro- to ferromagnetism can be also induced by an applied field for the antiferromagnetic compounds. The metamagnetic transition field decreases with increasing Ti concentration. The large magnetoresistance of up to 35% is observed at 5 K under 50 kOe for the compounds (0.4≤x≤0.6) with metamagnetic behavior. The evolution of the magnetic properties is discussed. © 2002 American Institute of Physics.